How to use astronomical spectra?

  • Context: Undergrad 
  • Thread starter Thread starter yucheng
  • Start date Start date
  • Tags Tags
    Spectra
Click For Summary

Discussion Overview

The discussion revolves around the use of astronomical spectra, specifically focusing on how to access and interpret data from various file formats such as VOTable, FITS, and ASCII. Participants explore methods for visualizing and analyzing spectral data, as well as seeking guidance on using spectroscopic databases.

Discussion Character

  • Exploratory, Technical explanation, Homework-related

Main Points Raised

  • One participant expresses confusion about opening a FITS file and questions whether the 2D spectra are contained in a single-dimensional array, seeking guidance on better viewing methods and online resources.
  • Another participant clarifies that the PNG file represents a graph of the spectrum, while the ASCII file contains a table of flux as a function of wavelength, suggesting that plotting these values will reproduce the PNG graph.
  • A different participant mentions using the Python library astropy.io.fits to open FITS files, noting that it provides the same flux vs wavelength data found in the ASCII file.
  • One participant shares a successful experience using a specific code from an external source to work with stellar spectra in FITS format.

Areas of Agreement / Disagreement

The discussion includes multiple viewpoints on how to handle and visualize spectral data, with no consensus on the best method or resource for beginners. Participants provide different approaches and tools without resolving the initial participant's confusion.

Contextual Notes

There are limitations regarding the assumptions about the data structure in FITS files, and the discussion does not clarify the specific requirements for successfully visualizing the spectra.

yucheng
Messages
232
Reaction score
57
TL;DR
Trying to open a FITS file to view stellar spectra....
As suggested here

http://svocats.cab.inta-csic.es/miles/index.php?action=search

I tried downloading the VOTable, and FITS file (tried opening using Aladin and GIMP). However, when I open the file, I get a single line (I suppose the 2D spectra is contained in a single dimensional array?). Did I open it correctly? Is there any online guide for this? Is there a better way to view the spectra? Would you suggest some guides to using spectroscopic databases in general? Thanks!
 
Astronomy news on Phys.org
What exactly are you looking for? The PNG file is a graph of the spectrum. The ASCII file is a text file with a table of the flux as a function of wavelength. If you plot those values you will reproduce the PNG file. The FITS file has the same flux vs wavelength data in FITS format.
 
I typically open FITS files using the python astropy.io.fits code, but it will give you the same table of flux vs wavelength that is in the ACSII file.
 
Reply
  • Like
Likes   Reactions: yucheng

Similar threads

Undergrad Software for Analysis of FITS table/spectra
  • · Replies 11 ·
Replies
11
Views
3K
How to read a column of data into Fortran without arrays? (Fortran 77)
  • · Replies 7 ·
Replies
7
Views
3K
Admissions Could I please get critique on my SOP? (Experimental Biophysics)
  • · Replies 9 ·
Replies
9
Views
1K
Python How to Edit Specific Lines in Files Using Python?
  • · Replies 18 ·
Replies
18
Views
2K
Undergrad Using PCA for variable reduction
  • · Replies 6 ·
Replies
6
Views
2K
Undergrad 7Li(p,e+e−)8Be direct proton-capture reaction X17
  • · Replies 7 ·
Replies
7
Views
3K
Minimum magnitude resolvable by a spectrograph
  • · Replies 2 ·
Replies
2
Views
2K
Fortran How to Write a 2D Array to a .dat File in Fortran90?
  • · Replies 11 ·
Replies
11
Views
3K
C/C++ [C++] Database Handler (simple)
  • · Replies 2 ·
Replies
2
Views
3K
How Do You Implement Pipelines and I/O Redirections in a Unix Shell Using C?
  • · Replies 1 ·
Replies
1
Views
4K